At present, most of servers generally adopt a storage structure where a plurality of disks is connected to a redundant array of independent disk (RAID, Redundant array of Independent Disk) controller. A plurality of disks in common use connected to the RAID controller may be flexibly configured to a RAID group, for example, 5 disks are configured to a RAID group.
In the case where a plurality of disks exists in a system, a plurality of disks under the control of the same RAID controller is configured to several RAID groups, for example, disks 1, 2, and 3 are configured to a RAID group, disks 4, 5, and 6 are configured to a RAID group, and disks 7, 8, and 9 are configured to a RAID group; and because data stored in each RAID group is generally different, an operating system distributes a drive letter to each RAID group for a user to use. For example, the RAID group formed by the disks 1, 2, and 3 has a drive letter of sdb and stores a file A; the RAID group formed by the disks 4, 5, and 6 has a drive letter of sdc and stores a file B; and the RAID group formed by the disks 7, 8, and 9 has a drive letter of sdd and stores a file C.
In the prior art, a drive letter of each RAID group is distributed by an operating system according to a sequence in which RAID groups are added. However, after every time the system is restarted or the disk is unplugged and plugged, it cannot be ensured that every time the RAID groups are added in the same sequence. Therefore, after every time the system is restarted or a disk is unplugged and plugged, the drive letter of each RAID group may be different so that the user cannot accurately find data stored in a RAID group.